Adjusting device for elevator boot-pulleys



G. L. GRASS. G DEVICE FOR ELEVATOR BOOT PULLEYS. APPUCATION FILED NOV. 21. 1919.

ADJUSTIN Patented Aug. 16, 1921.

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GEORGE LEWIS GRASS, OF TORONTO, ONTARIO, CANADA, ASSIGNOR TO DOIDGE MAN U- FACTURING COMPANY OF CANADA, LIMITED, OF TORONTO, CANADAV ADJUSTING DEVICE FOR ELEVATOR, BOOT-PULLEYS.

Specification of Letters Patent.

Patented Aug. 16 1921.

Application filed November 21, 1919 Serial No. 339,578

To all whom it may concern:

'Be it known that I, GEORGE L. 'GRAss, of city of Toronto, in the county ofYor'k,

rovince of Ontario, Canada, have invented certain new and useful Improvements in Adjusting Devices for Elevator Boot-Pulleys, of which the following is a specification.

This invention relates to elevators of the type in which an endless belt carrying buckets operates in housings connected at their lower ends by a boot. In the boot the belt passes around the boot pulley, and, owing to the fact that the length of the belt changes with changes in atmospheric conditions and changes in the load, it is neces sary to provide means for adjusting the position of theboot pulley.

My object therefore is to devise means for automatically taking up the stretch of the belt and means for insuring the belt running true on the pulley. A further object is to arrange the tensioning device'so that when necessary the boot pulley may be raised and the tension taken off the belt when the latter requires to be taken up.

I attain my objects by means of the constructions hereinafter described and illustrated in the acompanying drawings in which- V Figure 1 is a side elevation of the lower end of an elevator leg with the improved boot pulley adjusting device in position; and

Fig. 2 an end elevation of the same parts, partly in cross section and partly broken away.

In the drawings like numerals of reference indicate corresponding parts in the different figures.

1 and 2 are the vertical housings of the elevator leg through which the belt 20 carrying buckets 21 passes; the direction of movement being down the housing 1 and up the housing 2. 3 is the boot connecting the lower ends of the two housings. In the sides of the housing are formed openings 5, in which are fitted the vertical guides 9. In these guides slide the yoke frames 8 carrying the bearings 7 in which are journaled the ends of the shaft 6 carrying the boot pulle 4.

Ihe parallel adjustment means for the boot pulley includes two gear racks 10 set parallel with the housing 2, one on each side ofthe boot. -With these racks mesh spur pinions llrmounted on a shaft 12,'and carried journal boxes on the brackets 13. The shaft 12 is provided at each endwi'th a grooved wheel 14, on each of which is wound a chain 15, one end of which is attached to the wheel. At the other end of the chain is attached a nest of weights 16, which causes the shaft 12 to tend to rotate and the pinions 11 toexert pressure on each of the racks 10, which are connected to the hearing yokes 8 by the adjusting rods 17, each of which is provided with a thread and nut at one end whereby the bearings of the shaft carrying the pulley can be adjusted independently to perfectly aline the pulley with the belt.

18 is a roller placed against the back of each rack opposite its pinion 11 to keep the rack 10 in mesh with the pinion 11. These rollers are carried by a shaft 19 which passes from one side to the other and is carried in journal bearings on the brackets 13, which also carry the shaft 12. Each gear rack 10 is provided with a stop on the back which comes in contact with the roller 18 to prevent the possibility of the boot pulley being adjusted too near the bottom of the boot, or, in other words, places a limit to the adjustment of the pulley to prevent the buckets irom scraping on the bottom of the elevator oot.

At any time by reversing the winding of the chain or the grooved wheels the weight of the boot pulley may be taken off the belt so that the latter may easily be shortened as may be necessary. k

1 What I claim as my invention is .1. In a belt adjusting device, the combination of asupporting frame; a bearing located at each side of said frame movable relative to the frame and to each other; a shaft journaled in said bearings; a pulley carried by said shaft between said bearings a suitably guided rack connected to each of said bearings; a second shaft journaled on shaft journaled in said bearings; a pulley carried by said shaft between said bearings; a suitably guided rack at each side of said frame; connecting means between each of said racks and each of said bearings adjustable in length; a second shaft journaled on the supporting frame; a pinion secured adjacent each end of the last mentioned shaft and each meshing with a rack; weights; and means whereby the weights tend to rotate the last mentioned shaft.

3. In a belt adjusting device,- the combination of a supporting frame; abearing located at each side of said frame movable relative to the frame and to each other; a

shaft journaled in said bearings; a pulley carried by said shaft between said bearings; a second shaft journaled on thesupporting frame; a pinion secured adjacent each end of the last mentioned shaft; a rack slidably supported on each side of the frame and meshing with said pinions; rods connected at one end to said bearings, the other ends of said rods being'adjustably connected with said racks, weights; and means whereby the weights tend to rotate the last mentioned shaft. 1

Signed at Toronto this 12th dav of November, 1919.

GEORGE LEWIS GRASS. 

